1) Omni - I always figured it meant the slash was "all-encompassing" since it used so many different strikes in one attack
2) Double Strike ("cut" doesn't make sense for all the characters)
3) Quadruple Strike (Or Quadra if quadruple can't fit)
4) Quadruple Cast
5) I personally like "Muddle" but bewilder is probably better than mystify
6) Paradise is ok but also consider Escape, Delusion, Fantasy, Abandon.